Motor-driven compressor



Marcfi 23, 1954 T. CORNELIUS ETAL 3 1 MOTOR-DRIVEN COMPRESSOR RICHARD .T. CORNELIUS.

AND

-i- 6 BY NELSON F. CORNELIUS zfiwzflmw ATTORN S 4 Sheets-Shet 4 FIG. 8

I74 7 2 I77 I73 FIG.4

IN V ENT 0 R S RICHARD T. CORNELIUS AND NELSON F. CORNELIUS gm%o b% Y ATTORNE MOTOR DRIVEN COMPRESSOR March 23, 1954 Filed July 16, 1951 ,IIII

Patented Mar. 23, 1954 UNITED- sca -tes- MOTORL-DRIVEN COMBBESSORi Richard T. Cornelius, Minneapolis, and Nelson F."

Cornelius, Anoka; Minn.

Application July. 16, 1951, SeriaLNoi 236;!)86

1410mm... (Cl. $530- 187)" The; herein disclosed ifientionrelates t multipIestage compressors. of: the type having, a. crankzcase withghorizontallydisposed, radialcyl inders-communicating therewith andpanticularly to .the'oiling system. therefor andghas for an ob.-,

ject-"to .providean piling isystem by means of which sufficient lubrication may be 1prqcured for allyof .thepistons.

Another, obj ect: .rof th invention resides in equalizing the. pressure on both sides: of, the :low

pressure pistomduring-the suction stroke wherer by. oil may enter the.:-, sp ace; between the cylinder and piston and blow by thepiston.

An object of the, inventionresides in provide; i ing-a source ofair undeltrqpressure at a pressure,

highen-thanthe. maximumet Q p eric pr s ur at which the compressor-is to bei-used and in connecting. the, intake 0f theylow -pressure cylinder to said source of air;-

A. still; further, object Of ;theinvention resides in constructing. the: compressor with crank case having. a crank ,case; chamber and with cylinders communicating;therewith and in. providing a conduit connected to said source of airand to the,cranlccasezchamberu Anotherobiect attire-inv n n r sidesin com structing-certainof, the cylinders with enlarge-, meritsv adjacentthe crank case and in providing cross; heads in the enlargements-of the cylinders with universal; connections ,--between the; cross,

heads and pistons wherebysoil entering the cyle indersmay drain intothe en1argement and back into the crank case;

An object of the invention resides in thespe- -v ciiic construction of the universal connectionbetwcenthe, cross heads and pistons.

Anotherobject of the invention resides in arranging the outletsiorthe cylindersatthe lower portionsgof thersame and in running conduits fromrthe outlet of one stage to the-inlet of the following stage whereby oil accumulating in one cylindercoilects at the bottom thereof and drains into the outlet and thegconduiu connectedthereto and iscarried along with the air,,dis charge d,

from theone cylinder tothe following cylinder.

A stillv further object of theinventioniresides. in constructil' g the first ,eylinderof uniformbore so that oil.entering thesame. may flowpast the piston.

Another object of the inventionresides inproriding a construction whereb the oil is prevented. from completely flowing fromtheioil receptacle,

and intcthe cranl; casein the-eventofythecompressor. being-pperated at an angle. .or, comp1ete1y--,

o erturned-a a A still further object ;of-,the invention resides in providing. an oilingsystem in which a vent is pro-F- videdfor; discharging airinto the crank ,caseto a1low.,the; oiltodrain backinto theiroil reser -voir and, in constructing said vent so that the same will remain openv regardless ofJ-the .pQsi

tion of .thevcom-pressor.

Another object of the, invention reside in pro-. vidi gan oilreceptacle contacting the crank case. and adapted toibe urged into .engagement.there-,. with by means, of a springto whichthe recep tacle is attachedand .whichin .turnds secured...

to the oil pump.

Other objects of the invention .reside,in.,.the novel combination and ,arr,angements of..pa,1 ,ts,.,-. and in, the detailssof. construc ion herei 'aitfi r illustrated and/ordescribed;v

Inthe drawings;

Fig. 1 is an eleyational viewofra compressor. illustrating an embodimentpithe in ention.

Fig. 2 is ahplan sectional iew taken substane tiallyon 1ine2-7-2 of Fig. 1.

Fig. 3 is an elevational sectionaliview taken on line 33 of Fig. 2.

Fig. 4 isafragmentary elevationalsectional view taken on line 4+4 of Fig, 3.

Fig. 5 is a fragmentary elevational sectional view taken on line 5+5 of Fig. 2.

Fig. 6 is a fragmentary elevationalsectional view taken on line 6+6 of Fig. 5.

Fig. {7 is. a. fragmentary 1 eleyational. sectional view taken on line 'l-'-! "of Figs 3,'and drawnto a greater scale.

Fig. 8 is a fragmentary elevational sectional.

view taken on line 8'-8 of Fig. 3 anddrawn .to a reater scale.

In the drawings has been shown a multiple stage highpressure. compressor capable of pumping 3,000 :lbs. pressure per square inch and of relatively. light weight so that-the same may be installed on an airplane. This compressor com-.-

prises a crank .casehaving threeeylinders at,-

tached thereto, and extendingv radially. outwardly therefromgina horizontal direction. Above the,

I crankcase-and supported thereon is an electric motor havingwa vertical shaft extending intothe bore and has mounted in it a piston of uniform diameter. The higher pressure cylinders have enlargements at their inner ends. In the higher pressure cylinders are pistons which are connected by means of universal connections to cross heads slidably mounted in the enlargements. These cross heads are connected to and operated by the crank means. The inlet to the low pressure cylinder is connected to a source of air under pressure, the pressure of which is above the atmospheric pressure at the lowest altitude at which the compressor is to be used. A conduit connects the crank case chamber with said inlet so that the crank case pressure is equalized with respect to the inlet pressure. On the suction stroke of the low pressure piston oil is hence drawn into the low pressure cylinder, past the piston and into the compression chamber therein which is mounted a liner 4|,

of. The outlets from the higher pressure cylinders are on the bottom thereof and the inlets on top and conduits are connected from the outlet of one cylinder to the inlet of the other. B means of this construction the oil leaking past the low pressure piston is successively passed through the various high pressure cylinders. As it travels the oil passing by the pistons therein is drained back into the crank case, thus lubricating all of the pistons. The lower portion of the crank case has secured to it an oil pump which is driven from the crank pin and which delivers oil into the crank case chamber. This pump is disposed below the crank case and is received in an oil receptacle which is removable and which engages the crank case to form a fluid-tight connection therewith. A spring secured to the pump has attached to it a nut into which is screwed a screw engaging the oil receptacle. By means of this construction the oil receptacle is yieldingly held in engagement with the crank case. To procure ready return of oil to the receptacle an air vent is provided which communicates at one end with the crank case chamber. The other end of this air vent communicates with the interior of the receptacle through an annular passageway encircling a funnel in which the oil discharged into the crank case chamber is received.

The compressor of the invention utilizes a crank case I0 constructed with side walls II and i2, and a front wall I3. The upper portion of the case Ill has a wall structure I6 serving a purpose to be presently described and the lower portion is open and surrounded by a. flange l1. This crank case has a crank case chamber l5 within the same and into which certain of the moving parts of the compressor are disposed.

Mounted on the upper portion of the crank case ii! is an electric motor [8. This motor comprises a core l9 disposed in a tubular housing 23). Screw 2| extending through the housing and screwed into the core hold the same attached to the housing. On the core l9 are windings 22l which produce the magnetic field for the motor. The core 29 is formed with a bore 22 in which is rotatably mounted an armature 23. This armature has a core 24 in which are wound windings 255 connected to a commutator 25. Since motors of the class shown are well-known in the art the motor has not been shown in detail. The armature 23 has an armature shaft 21 which is rotatably supported at its lower end in a bearing 28 mounted in a socket 29 formed in the lower end of a boss 30 forming part of the wall structure l6 and which serves as the lower end bell for the motor. The upper end of the shaft 21 is journalled in a bearing 3| which is similarly 4 mounted in a bore 32 formed in an end bell 33 mounted on the housing 20. This end bell has an annular recess 34 in which the housing 20 is received and a flange 35 forming part of the Wall structure I6 is likewise formed with a recess 36 in which the lower end of the housing is received. Issuing outwardly from the end bell 33 are lugs 38 through which bolts 39 extend. These bolts are screwed into corresponding lugs 3'! issuing outwardly from the flange 35. By means of this construction the parts are rigidly clamped together.

Mounted on the wall 13 of crank case I0 is a low pressure cylinder 40 best seen in Fig. 2. This cylinder is formed with a flange 25l which overlies the wall I3 and is secured thereto by means of screws 252. Cylinder 40 has a bore d5 This liner in turn has a. bore 43 in which is slidably positioned a piston 42. The said liner and the inner end of the cylinder 40 extend through an opening 34 in the wall l3 of crank case Iii so that the interior of the cylinder 40 is in direct communication with the chamber It in the crank case 10. The bore 45 of cylinder ii! is formed with an enlargement 45 at its outer end which forms a shoulder 18 against which a flange 24"! formed on the liner 4| is seated. The outer end of the liner 4| forms a valve seat against which a disc valve member 4! is seated which is best shown in Fig. 5. This valve member has lugs i8 projecting outwardly from its edges which engage the enlarged portion 46 of the bore 35 and guide the disc for axial movement. This construction also provides air passages 49 between the lugs 48 through which the compressed air may pass in leaving the cylinder. This disc t! is held in engagement with the end of the liner 4| by means of a compression coil spring 50 which is seated against a cup-shaped member 5|. This member is bolted by means of a bolt 53 to a plate 52 which covers the open end of the cylinder 40. Plate 52 is attached to the cylinder 40 by means of screws 54.

The end 55 of armature shaft 2"! has attached to it a crank 56 which is formed with the usual crank pin 51. This pin has a ball bearing 58 mounted on it and which i also mounted in a boss 59 integral with a connecting rod 66. This connecting rod is pivoted by means of a wrist pin 6| to the piston 42. Rotation of the shaft 21 causes the connecting rod 60 to be operated and the piston 42 to be reciprocated in the usual manner.

The inlet to the cylinder 40 is to one side of the cylinder as shown in Fig. 2 and consists of a threaded boss 62 in which is screwed a fitting 63. This fitting has screwed into it a T 63, one leg of which is attached to a nipple 65 adapted to be connected to a source of air under pressure. The said T i further connected to a tube 55 which in turn is connected to a fitting El tapped into the wall l3 of the crank case M). By means of this construction the chamber E5 of crank case it is brought in communication with the inlet to the low pressure cylinder and the pressure in said crank case chamber equalized with the pressure in the cylinder proper during the suction stroke of the piston 42. The inlet 62 is in communication with an annular groove 3% formed in the cylinder 40 and which communicates with a number of ports 69 formed in the liner 4}. These ports permit air to enter an annular space H! encircling the piston d2 intermediate the ends of the same. The piston rams:

aye-moss ayalv *"H ,formed'in the'head of the same and air entering the space 10 may pass through p sag'eways 12in the piston 42;, past the valve andinto thespace 13 at the head of the piston. The piston 42- on'its pressure stroke compresses the air in the chamber 73 forcing it past the valve member 41 and into a chamber I4 formed in the enlargement 45 of the bore of the cylinder. As best shown in Fig. 5 a fitting I5 is screwed into a boss *1! formed on the cyinder 40. This fitting has connected to it an elbow I8 which in turn is connected to a tube 19 lead-ingto the intermediate pressure cylinder -80.

"The intermediatepressu-re cylinder 80 is similar to the cylinder -40'=and has a flange "81 overlying the wall H of crank case I and secured thereto by means of screws '82. The said cylinder, asbest shown in Fig. '3, is formed with a bore 83* having an enlargement at its outer end and another enlargement at its inner end. In the cylinder proper is mounted a liner 8.6 which is constructed similar to the liner 4| of cylinder 40 and which is mounted in position therein in the same manner. This cylinder'has a -disc valve 81 atthe outer end of the liner 86- imilar to the valve 41- which is held in engagement with the end of said liner by means of a compression coil spring 80. This spring is seated against a'plug 8'9 screwed into the end of the cylinder '80. Within the liner 36 is mounted for reciprocating movement a piston 90". In the enlargement 05 of bore '83 mounted a liner 9I' which has a flange 92 on the same clamped in between the flange 8II- and the wall I- I of the crank case. In this liner is slidab'ly mounted a cross head 93 which is formed with an end Wall 94. This end wall has a circular "-hole '95 in the same and which communicates with a slo't' 06 extending through said end wall and through the cross head proper as best shown in Fig. 4. formed a groove 9 which serves as a throat and which receives the portion of th end wall 94 of cross head 93 adjacent the hole 05 and connects the two parts'together. By means of this construction the piston is universally connected to thecross head. The :cross head 93 is connected to a connecting rod 93 by means of a wrist pin 99. Thisiconnecting rod .in turn is connected by means of another wrist pin I00 to lugs :I'01I formed on the boss 59 of the connecting rod :60. By

means 0t this construction the cross head 93 and the piston 190 are simultaneously reciprocated and the piston 90 floats within the liner :83 of. cylinder 80 so that no lateral strains are placed upon the same so that an extremely tight tfit may be made between .the piston and the liner. An inletfitting I02 is screwed in a boss I03 formed on the cylinder 80 at the upper portion of the same. This inlet communicates with a port 104 formed :in the liner '86 and which in turn communicates with the chamber I05 formed/at the head end :of the piston-90, The fitting 102 has connected toit an L I06 which in turn is connected to the tube .19 leading from the cylinder '40. The :outer end. .of the :cylinder .80 isv .iormed with a boss which is threaded .to---receive.-.a fitting 1:08. This fitting. has secured toit an L; :I09, best shown iin1Fig. 1, and which is connected to an outlet tube 1 I10. cates with .a passageway III which inturn communicates with thewchamloer II2 formed in the enlargement 84 of the bore 83.

."Ih' ztube. I10. o'er-connected to an elbow I. I:.6

In the piston .90 is The fitting I08 comm-unhin turn is connected to? aux-inlet: Facing. 4. 16571:

6. inder is constructed similar to the cylinder excepting that the same-is of smaller dimensions and that piston II 5 of the same is of smaller diameter. The said piston is connected to a cross head II! which is slidable in a liner I'8-I similar to the liner 9|. A connecting rod II-8 connects the cross head I I 'I-'-to a wrist pin 113 which is'mounted in lugs 420 formed on the bos 559;

The cylinder 114 has an outlet fitting Hi to which a suitable conduit may be connected and which-leads to the reservoir in which the compressed air is maintained. Another outlet .2 53 :is

employed into which anipple 254 is screwed and which-is connected to a pressure-switch gage or similar device Due to the similarity of the cylinder IIIA and the cylinder -80 and associated par-ts, thedescription thereof will not be repeated though it can be readily comprehended that the construction con-forms :to that illustrated in connection with thecylinder '80.

Lubrication of the moving parts of the compressor-is procured from oil indicated at 122 and contained within anoil receptacle I23. This receptacle has a spheroidal .bowl I24 at the lower portion thereof and a cylindrical portion 125 above the bowl. The cylindrical portion termimates in :an upwardlyxextending sleeve 12 3, best shown in'Fig. 7, which fits over the flange I! of crank case 1'0. An O-ring 12.1 forms a tight connection :between said sleeve and flange.

"Thelowermost portionrof the case1I0, as previously described is open and is closed by means of a :cover 172 BI. .c'overis screwed to the flange I] by means of screws 129. The cover I20 has a funnel I30 cylindrical in :torm depending therefrom and which has =:a bottom I31. Issuing upwardly from th bottom is apartition I32 whichprovides at its upper end a bearing I33 tor a vertical shaft 134. Partition 132 has a bone I35 forming a passageway within the sameand which is iopen at the bottom and communicates with the interior of the receptacle :I'2-3. The funnel I230has :a chamber I36 within thesame and which communicates through opening I31 in the partition 1:32 with the bore 135 and thus comm-unicates with the interior of the receptacle I23. Extending downwardly from the funnel I30 is an arm 138- whichsupports a gear pump I 39. This gear pump has a case 1 40 in which the gears I-'.4.2"or the pump are disposed. The shaftI34 is journaled'in a bearing .I-4I formed in the pump case I40 and has attached to it one of the gears I:4-2 :Of the gear pump. The inlet to the gear pump' consists of .an opening I46 in the case 140 which is in communication with the bowl I24 of the receptacle I23 and the oil 122 in which the pump is immersed flows directly into this hole and into-the pump proper. The outlet of the pump discharges through a passageway I43 in a tube 141 connected to case I40 and forming part of partition 1.32 and is discharged through a nozzle 1:44 extending above the cover 128 and discharging upwardly against the crank structure including the crank 56 and the associated parts.

For the purpose of directing air into the crank case chamberl 5 .a ventis employed which .is constructed as follows: Encircling the funnel I30 is a ring 148.. This ring is formed. with an annular groove TI 49 forming in conjunction with the outer surfac of thebowl an annular passageway. As shownzin .Fig. the partition I32 is formed with a tube I50 which has a passageway .I5I ..com-. munioati'ng with the passageway 149 pn lone side Otzthe :funnel. 0n the-other side :of the funnel I36 the ring I48 is formed with an outlet I52 which discharges into th interior of th receptacle 23. By means of this construction air is directed from the receptacle I23 through the passageways I49 and I5I and into the chamber I5 to vent the receptacle I23.

The shaft I34 is driven by means of a flanged bushing I53 which has a slot I54 formed in the same. A pin I55 issuing downwardly from the crank pin 51 is received in this slot. The shaft I34 is axially disposed with reference to the motor shaft 21 and rotation of the pin I55 serves to drive the gear pump I39.

The receptacle I23 .is held attached to the case I0 by means of the following construction best shown in Figs. 3 and 7. The pump I39 is secured together by means of bolts I82. These bolts also attach to the pump case I a leaf spring I56. This spring is formed with a horizontal lower reach I51 which has secured to the center of the same a nut I58. A screw I59 extends through the bowl I24 of receptacle I23 and screws into the nut I58., This screw has a hand wheel I BII by means of which the same may be rotated and a washer I6I which engages the inner part of the bowl I24 holds the said screw from disengagement from the bowl. When the screw I59 is engaged with the spring I51 the bowl is resiliently urged against the case II] of the compressor and thus secured from movement to form a fluid-tight connection with the case.

To prevent loss of oil from the crank case III and outwardly past the bearing 28 the following construction is employed. The shaft 21 has a reduced portion 55, previously referred to, and which is journalled in the bearing 28. Also mounted on this reduced portion is an oil slinger I 62 which consists of a web I63 having holes I64 in the same. This oil slinger has a hub I65 which fits on the reduced portion of the shaft 21 and is held in place thereon by suitable means not shown. Depending from the web I63 is a flange I66 which fits closely to a turned portion I61 formed in the boss 30. These parts fit close enough to prevent the free passage of oil past the slinger and yet are not so tight but what the compressor may rotate freely. Extending across the space between the hub I and flange I66 is a screen I68, a felt disc I69 and another screen I10. A snap ring I1I holds the parts in position. Any oil discharged by the slinger I62 is collected by grooves I12 formed in the boss 30 and drains back into the crank case chamber I5. Above the oil slinger I62 is mounted a conventional oil seal I13. This seal comprises a flexible annular member I14 held against a collar I15 by means of a cage I16 and a com-.- pression coil spring I11. This spring is seated against a floating collar I18 which rides on a disc I19. By means of this construction oil is prevented from passing into. the interior of the motor I8.

Cooling of the entire compressor including motor I8 is accomplished by means of a fan 248 which is attached to the upper end of the shaft 21. This fan is somewhat larger than the mo-' tor housing 20 and air is directed past the motor proper as well as against the same and reaches the various cylinders of the compressor to also cool the compressor. A guard 2'49 en-' closes fan 248 and is secured to the end bell 33 by means of, screws 250.

The operation of the invent ion is-Ipbvidus. III-.-

case chamber I5. Here the oil is distributed to the various cylinders and the connecting rods and cross heads lubricated. Due to the crank case chamber being at the same pressure as the pressure in the air inlet, oil flows past the first piston on the suction stroke and into the air stream. The oil is then successively directed into the other cylinders and lubricates the same. Any oil blowing by the pistons in these cylinders drains back into the crank case chamber. The oil not picked up by the moving parts flows through funnel I30 and the holes I31 back to the oil receptacle. The oil in the chamber I5 is replaced by air taken from the crank case chamber l5 through the passageways I5I and I49. If the compressor becomes inverted the oil in the bowl I24 flows into the cylindrical portion l2 5 of receptacle I23 without flowing through the passageways I49 and NH. Inclination of the compressor does not plug the vent and prevent air moving in passageways I49 and I5I.

The advantages of the invention are manifest. Lubrication is procured for the compressor and parts in a manner such that waste of lubrication is prevented. Lubrication will at all times be available regardless of the position of the compressor. Should the compressor be momentarily inverted the oil will flow from the bowl to the cylindrical portion without flowing out through the vent. Thus the crank case chamber is prevented from being flooded with oil. The vent being open to the oil receptacle on the side of the funnel opposite the opening thereof to the crank case chamber, flow of oil in the vent is greatly restricted.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. In a multiple stage compressor a crank case having a crank case chamber, a low pressure cylinder and a higher pressure cylinder, both having their inner ends communicating with said crank case chamber, pistons in said cylinders, crank means within said crank case chamber pivotally connected to and operating said pistons, an oil receptacle, oil distributing means including a conduit extending between said oil receptacle and said crank case chamber for delivering lubricating oil from the oil receptacle to the crank case chamber the oil in said crank case chamber being splashed into the inner end of said low pressure cylinder and equalizing means communicating with and equalizing the pressure on both sides of said low pressure cylinder during the suction stroke thereof.

2. In a multiple stage compressor, a crank case having a crank case chamber, a low pressure cylinder and a higher pressure cylinder both horizontally disposed and having their inner ends communicating with said crank case chamber, an oil reservoir, a cross head slidable in said higher pressure cylinder, a piston slidable in the same cylinder, a universal connection between said cross head and piston, a piston in said low pressure cylinder, means communicating with and delivering oil from said oil receptacle to said low pressure cylinder and discharging the same into'the pressure chamber of the-low pressure cylinder,.'a discharge conduitbetween the bottom of saidlow pressure cylinder and the inlet to said higher pressure cylinder and directing oil passing by the low pressure piston into the higher pressure cylinder and past said higher pressure piston and cross head and back into said crank case.

3. In a compressor, a crank case having a crank case chamber, a cylinder communicating therewith, said cylinder having a concentric enlargement adjacent said crank case, a piston disposed in said cylinder and forming therewith a pressure chamber, said piston having an annular groove in the same at the end thereof nearest said crank case and forming a throat therein and a flange at the, end of the piston, a cross head disposed in said enlargement of the cylinder,.said cross head having'an end wall and a skirt slidable insaid enlargement, said end wall having a circular hole therein concentric with the piston and of a diameter to receive said throat-said end wall having a slot therein extending through said skirt and said skirt having an opening communicating with said slot and through which said flange may be directed whereby the piston and the cross head may be assembled by relative transverse movement therebetween.

4. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicating therewith, a piston in said. cylinder, crank means-in said crank case pivotally connected to and operating said piston, said crank case being open at the bottom, a closure attached to the lower end of the crank case, a funnel formed on said closure and extending below the same, an oil pump mounted on said funnel and disposed below the same, means forming a passageway between the outlet of the pump and the crank case chamber, an oil receptacle attached to the lower portion of said crank case and receiving said funnel and pump, said funnel having a passageway at the lowermost portion thereof communicating with and directing oil entering the funnel back into the receptacle, a ring encircling said funnel and having an annular passageway therein and being formed with an opening on one side of the funnel and an air duct having a passageway connected to said annular passageway on the other side of the funnel, said duct extending upwardly beyond the uppermost portion of the funnel.

5. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicating therewith, a piston in said, cylinder, crank means in said crank case pivot-ally connected to and operating said piston, a funnel at the lower portion of said crank case having an opening at the top communicating with and re-, ceiving the oil discharged into said crank case chamber, an oil pump disposed below said funnel, means forming a passageway between the outlet of the pump and the crank case chamber, an oil receptacle disposed at the lower portion of said crank case and receiving said funnel and pump, said funnel having a passageway at the lowermost portion thereof communicating with and directing oil entering the funnel back into the receptacle, a ring encircling said funnel and having an annular passageway therein and being formed with an'opening on one side of the funnel and an air duct having a passageway connected to said annular passageway on the other side of the funnel, said duct extending upwardly beyond the uppermost portion of the funnel. 6. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicating therewith, a piston in said cylinder, crank means in said crank case pivotally connected to and operating said piston, a funnel at the lower portion of said crank case having an opening at the top communicating with and receiving the oil discharged into said crank case chamber, an oil pump disposed below said funnel, means forming a passageway between the outlet of the pump and the crank case chamber, an oil receptacle disposed at the lower portion of said crank case and receiving said funnel and pump, said funnel having a passageway at the lowermost portion thereof communicating with and directing oil entering the funnel back into the receptacle, and means including an air duct extending between said crank case chamber and the spacewithin said receptacle, said duct having an opening disposed above the uppermost portion of said funnel.

7. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicatingtherewith, a piston in said cylinder, crank means in said crank case pivotally connected to and operating said piston, a funnel at the lower portion of said crank case having an opening at the top and receiving the oil discharged into said crank case chamber, an oil pump disposed below said funnel, means forming a passageway between the outlet of the pump and the crank case chamber, an oil receptacle disposed at the lower portion of said crank case and receiving said funnel and pum said funnel having a passageway at the lowermost portion thereof communicating with and directing oil entering the funnel back into the receptacle, said receptacle having a space above the passageway in the funnel leading to the receptacle of at least as great a volume as the volume in the receptacle below said passageway.

8. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicating therewith, a piston in said cylinder, crank means in said crank case pivotally connected to and operating said piston, a funnel at the lower portion of said crank case having an opening at the top and receiving the oil discharged into said crank case chamber, an oil pump disposed below said funnel, means forming a passageway between the outlet of the pump and the crank case chamber, an oil receptacle disposed at the lower portion of said crankcase formed with a globular portion receiving said pump and with a cylindrical portion receiving said funnel, said funnel having a passageway at the, lowermost portion thereof communicating with and directing oil entering the funnel back into the receptacle, said cylindrical portion having a volume at least as great as the volumeof said globular portion.

9. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicating therewith, a piston in said cylinder, crank means in said crank case pivotally connected to and operating said piston, a funnel at the lower portion of said crank case having an opening at the top and receiving the oil discharged into said crank case chamber, an oil pump disposed below said funnel, means forming a passageway between the outlet of the pump and the crank case chamber, an oil receptacle disposed at the lower portion of said crank case formed with a globular portion receiving said pump and with a cylindrical portion receiving said funnel, said funnel having a passageway at the lowermost portion thereof communicating 11 with and directing oil entering the funnel back into the receptacle, said cylindrical portion having a volume greater than the volume of said globular portion.

10. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicating therewith, a piston in said cylinder, crank means in said crank case pivotally connected to and operating said piston, an oil pump supported by the crank case and disposed below the same and discharging into said crank case chamber, means for driving said oil ump from the crank means, an oil receptacle disposed below said crank case and engageable therewith and receiving said pump, a spring attached to said pump and disposed below the same, a threaded member carried by said spring and a complemental threaded member carried by said receptacle and engaging the threaded member on said spring to cause said spring to yieldingly act on said receptacle and to urge the receptacle into engagement with said crank case.

11. In a compressor, a crank case having a chamber therein, a cylinder having its inner end communicating therewith, a piston in said cylinder, crank means in said crank case pivotally connected to and operating said piston, an oil pump supported by the crank case and disposed below the same and discharging into said crank case chamber, means for drivin said oil pump from the crank means, an oil receptacle disposed below said crank case and engageable therewith and receiving said pump, a looped leaf spring attached to said oil pump and having a portion extending transversely thereof and below said pump, a threaded member carried by the denoted portion of said spring and a complemental threaded member carried by said receptacle and engaging the threaded member on said spring to cause said spring to yieldingly act on said receptacle and to urge the receptacle into engagement with said crank case.

12. In a multiple stage compressor a crank case having a crank case chamber, a low pressure cylinder and a higher pressure cylinder, both having their inner ends communicating with said crank case chamber, pistons in said cylinders, crank means within said crank case chamber, connected to and operating said pistons, an oil receptacle adjacent said crank case, oil distributing means including a conduit extending between said oil receptacle and said crank case chamber, for delivering lubricating oil from the oil receptacle to the crank case chamber, the oil in said crank case chamber being splashed into the inner end of said low pressure cylinder, a conduit connected to and conducting air under a regulated pressure higher than the maximum atmospheric pressure in which the compressor is to be operated to the intake of the low pressure cylinder and a conduit connected to and conducting air under like pressure to said crank case chamber.

13. In a multiple stage compressor a crank case having a crank case chamber, a low pressure cylinder and a higher pressure cylinder, both having their inner ends communicating with said crank case chamber, pistons in said cylinders, crank means within said crank case chamber pivotally connected to and operating said pistons, an oil receptacle, oil distributing means including a conduit extending between said oil receptacle and said crank case chamber, for delivering lubricating oil from the oil receptacle to the crank case chamber, the oil in said crank case chamber being splashed into the inner end of said low pressure cylinder, a conduit connected to and conducting air under a regulated pressure higher than the maximum atmospheric pressure in which the compressor is to be operated and to the intake of said low pressure cylinder, and a conduit connected to said first named conduit and to said crank case chamber.

14. In a multiple stage compressor a crank case having a crank case chamber, a low pressure cylinder and a high pressure cylinder, both having their inn-er ends communicating with said crank case chamber, pistons in said cylinders, crank means within said crank case chamber pivotally connected to and operating said pistons, an oil receptacle, oil distributing means including a conduit extending between said oil receptacle and said crank case chamber, for delivering lubricating oil from the oil receptacle to the crank case chamber, the oil in said crank case chamber being splashed into the inner ends of said low pressure cylinder, a fitting connected to and conducting air under pressure and to the low pressure cylinder and a conduit connected to said fitting and to the crank case and bringing the pressure in said crank ease up to the pressure in said fitting.

RICHARD T. CORNELIUS.

NELSON F. CORNELIUS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,008,519 Barr Nov. 14, 1911 1,240,925 Bennett Sept. 25, 1917 2,048,025 Phillip July 21, 1936 2,247,449 Neeson July 1, 1941 2,294,619 Kastler Sept. 1, 1942 FOREIGN PATENTS Number Country Date 149,604 Austria 1937 

